Fluidized, dry bed, ore concentrator

Abstract

A fluidized, dry bed, ore concentrator in which a uniform air stream is utilized to fluidize ore particles within a region defined in part by two, moving, riffled surfaces. The particles are statically charged to enhance separation of particles within the fluidized mass. The less massive of the like-charged, fluidized particles are drawn off by a first riffled surface and denoted "tailings". The more massive, and valuable, of the particles are drawn off by the second of the two riffled surfaces and denoted as "fines".

That which is claimed is: 
     
       1. A fluidized, dry bed, concentrator comprising: means for fluidizing a mass of dry particulate material so as to physically segregate within the fluidized mass relatively heavy particulates from relatively light particulates; and   means coupled to the fluidizing means for withdrawing from said fluidized mass selected particulate matter so physically segregated wherein said means for withdrawing selected particulate matter comprises:   first extraction means coupled to a region of said fluidized mass in which relatively light particulate matter is segregated for extracting from said fluidized mass said relatively light particulate matter; and   second extraction means coupled to a region of said fluidized mass in which relatively heavy particulate matter is segregated for extracting from said fluidized mass said relatively heavy particulate matter.   
     
     
       2. The concentrator of claim 1 wherein said means for fluidizing said dry mass comprises air percolation means for percolating air through the mass of dry particulate material. 
     
     
       3. The concentrator of claim 2, further comprising means, coupled to said fluidizing means, for electrostatically charging the particulate material in said fluidized mass so as to further enhance said physical segregation of particulates within said mass. 
     
     
       4. The concentrator of claim 3 wherein said means for electrostatically charging said particulate material further comprises means, coupled to said air percolation means, for electrostatically charging the air percolating through the mass of dry particulate matter. 
     
     
       5. The concentrator of claim 1, further comprising means, coupled to said fluidizing means, for electrostatically charging the particulate material in said fluidized mass so as to further enhance said physical segregation of particulates within said mass. 
     
     
       6. The concentrator of claim 5 wherein said means for electrostatically charging said particulate matter comprises means, coupled to said fluidizing means, for percolating electrostatically charged air as a fluidizing medium through said mass of dry particulate matter. 
     
     
       7. The concentrator of claim 6 wherein said means for electrostatically charging said particulate material further comprises means, coupled to said air percolation means, for electrostatically charging the air percolating through the mass of dry particulate matter. 
     
     
       8. A fluidized, dry bed, concentrator comprising: means for fluidizing a mass of dry particulate material so as to physically segregate within the fluidized mass relatively heavy particulates from relatively light particulates; and   means coupled to the fluidized means for withdrawing from said fluidized mass selected particulate matter so physically segregated   wherein said means for withdrawing selected particulate matter comprises:   a first withdrawal belt, being a continuous driven belt of a structure which permits air flow therethrough, and having a first surface defining the upper bounds of a fluidizing air plenum;   a second withdrawal belt, being a continuous driven belt of a structure which permits air flow therethrough, and having a second surface defining the lower bounds of a fluidizing air plenum; and   means, coupled to said belts, for driving said first and said second withdrawal belts such that relatively light particulates are drawn off from the upper region of the fluidized mass by said first surface of said first belt, and relatively heavy particulates are drawn off from the lower regions of the fluidized mass by said second surface of said second belt.   
     
     
       9. The concentrator of claim 8, further comprising means, coupled to said fluidizing means, for electrostatically charging the particulate material in said fluidized mass so as to further enhance said physical segregation of particulates within said mass. 
     
     
       10. The concentrator of claim 9 wherein said means for electrostatically charging said particulate matter comprises means, coupled to said fluidizing means, for percolating electrostatically charged air as a fluidizing medium through said mass of dry particulate matter. 
     
     
       11. The concentrator of claim 8, further comprising means, coupled to said fluidizing means, for electrostatically charging the particulate material in said fluidized mass so as to further enhance said physical segregation of particulates within said mass. 
     
     
       12. The concentrator of claim 11 wherein said means for fluidizing said dry mass comprises air percolation means for percolating air through the mass of dry particulate material. 
     
     
       13. The concentrator of claim 12 wherein said means for electrostatically charging said particulate material further comprises means, coupled to said air percolation means, for electrostatically charging the air percolating through the mass of dry particulate matter. 
     
     
       14. The concentrator of claim 13 wherein said first withdrawal belt and said second withdrawal belt are each provided with riffles, coupled individually to said first and said second surfaces thereof and extending selected distances into the fluidizing air plenum defined in part by said first and said second belt surfaces. 
     
     
       15. The concentrator of claim 14 wherein said means for driving said first and said second withdrawal belts further comprises means for driving each of said belts independently at selected variable speeds. 
     
     
       16. The concentrator of claim 14 wherein said means for driving said first and said second withdrawal belts further comprises means for driving each of said belts in independently selected relative directions. 
     
     
       17. A method for fluidizing and concentrating a mass of dry particulate material comprising the steps of: a. using two driven, air permeable, continuous, riffle belts to define, between adjacent surfaces of said belts, an upper and a lower region of an air plenum;   b. introducing a mass of dry particulate matter into the air plenum so defined;   c. percolating air through said dry particulate matter within said air plenum so as to fluidize said dry particulate matter and cause a stratification of particulate matter therein in accord with the mass of the particles comprising the dry particulate matter, the heavier particles stratifying in the lower regions of the fluidized material;   d. using a first of said riffle belts to draw off particulate material stratified in the upper region of said air plenum; and   e. using the second of said riffle belts to draw off particulate material stratified in the lower region of said air plenum;   whereby separate concentrations of heavy particulate matter and lighter particulate matter are accumulated.   
     
     
       18. The method of claim 17 further comprising the step of electrostatically charging said particulate matter to enhance segregation and stratification of particles within said air plenum. 
     
     
       19. The method of claim 18 wherein the step of electrostatically charging said particulate matter comprises the step of electrostatically charging the percolating air used to fliudize said particulate material. 
     
     
       20. The method of claim 19 wherein the step of electrostatically charging said percolating air comprises the step of first passing said air through a charge-transfer material. 
     
     
       21. The ore concentrator apparatus for fluidizing and concentrating a mass of dry particulate material produced by practice of the method of claim 20. 
     
     
       22. The ore concentrator apparatus for fluidizing and concentrating a mass of dry particulate material produced by practice of the method of claim 19. 
     
     
       23. The method of claim 18 wherein the step of using two driven riffle belts comprises the further step of driving each of said two belts independently of the other. 
     
     
       24. The ore concentrator apparatus for fluidizing and concentrating a mass of dry particulate material produced by practice of the method of claim 23. 
     
     
       25. The ore concentrator apparatus for fludizing and concentrating a mass of dry particulate material produced by practice of the method of claim 18. 
     
     
       26. The ore concentrator apparatus for fluidizing and concentrating a mass of dry particulate material produced by practice of the method of claim 17.